With extra firm tofu- the best way to prep it is to thinly slice it (like 1/8 inch thick) and lay it out on paper towels to drain off excess water. Then sautee in a pan until brown, you can add it to any recipe, or sub it for chicken. It really takes on the flavor of whatever you're cooking with it.
Silken tofu is good in an egg-salad (crumble and mix with chopped eggs)
Silken tofu is also good in smoothies and desserts.

My friends dd used to love it raw and cubed. I tried it several times with dd#1 and she would never go for it. With #2, I completely forgot to give it a try. (it is not something I buy often) #2 used to love cubed avocado......

It tastes good in smoothies. It's also really good grilled (although it's to cold for that now). You could use it in puddings. Or use it in place of cottage or ricotta cheese in recipes. Personally I don't like it plain but it does take on the flavor of whatever you cook it with.
Also the books 366 ways to cook tofu and other meat alternatives and Horizons cookbook have a lot of great tofu recipes. Although I don't know how many would be appropriate for a baby. There are a lot of other tofu cookbooks available too, check your library.